Ricoh A-P4, Service Manual

Page: 159 / 381

The machine cannot detect the fusing unit
when the front cover and right cover are
closed.
• Fusing unit connection loose
557 C
Zero-cross frequency over
• Noise on the ac power line
The applied power ac frequency was de-
tected less than 66 Hz more than 10 times,
or less than 44 Hz one time.
559 A
Fusing unit jam • Remove the paper that is stopped in
the fusing unit.
• Check that the fusing unit is clean and
has no obstacles in the paper feed
path.
• If the error persists, replace the fusing
unit
The fusing exit sensor detected a fusing unit
paper late jam three times. The paper was
late and the fusing exit sensor could not de-
tect the paper three times.
• SC559 code does not operate until SP1109 has been set to "1" (ON). This sets the machine to count
the number of occurrences of paper late jams in the fusing unit. The default setting is "0" (OFF).
• SC559 is issued after the third occurrence of a paper late jam in the fusing unit. Once this SC has
been issued, the machine cannot be used until the service technician removes the cause of the jam
and restores it to normal operation.
• The jam counter is reset after a sheet of paper successfully passes the fusing exit sensor after the cause
of the jam has been removed.
620 D
Communication timeout error between
BICU and finisher • Serial line connecting BICU and fin-
isher unstable
• External noise
• BICU board and finisher main board
connection defective or loose
• Finisher main board defective
• BICU board defective
The BICU did receive a response within 100
ms after 3 attempts after sending data to the
finisher.
621 D
Communication timeout error between
BICU and finisher
• Serial line connecting BICU and fin-
isher unstable
• External noise
4. Troubleshooting
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